Estimation Of Wind-blown Dust Emissions In Hebei Province Based On CLM4.5

With the continuous developments of the economy and society,the problem of air pollution in China is becoming more and more serious especially in Hebei Province.Currently,Hebei Province has been one of the most serious areas of air pollution in China.The contribution rate of soil wind-blown dust to atmospheric pollutant PMio is usually between 20%?60%.The wind-blown dust emitted from the earth's surface to the atmosphere,has become one of the main components of air pollutants.The wind-blown dust has significant impacts on atmospheric phenomena and consequently on air quality.The wind-blown dust not only causes atmospheric pollution,but also changes the radiation balance of the ground and the acidity or alkalinity of the aerosol.It not only affects human health but also causes changes in the global climate system and ecosystem.A lot of scholars begin to pay attention to the study of the wind-blown dust emissions because of the environmental problems caused by wind-blown dust.A lot of semi-mechanism models were proposed based on the sandstorm physics theory by the indoor wind tunnel experiment and field observation to simulate the emission of wind-blown dust.These models can simulate the temporal and spatial distribution of wind-blown dust emissions,but there are significant differences between different models,even up to several orders of magnitude.So the wind-blown dust model still needs more and more further regional verification to improve the simulation.The ground air condition,vegetation cover ratio and soil characteristic parameters should be considered as far as possible to improve the performance of simulation.Therefore,this study simulated wind-blown dust emission of PM10 in 2013 in Hebei province based on the CLM4.5 wind-blown dust model.In order to evaluate the PM10 of Hebei province in atmospheric pollutants which are caused by wind-blown dust,the article set up parameters system of wind-blown dust productions by Community Land Model version 4.5(CLM4.5)using remote sensing data,the ground meteorological data,Land Data Assimilation System and Land Surface Characteristic Parameters Production etc.The factors affecting the wind-blown dust include soil moisture,wind speed and the proportion of bare soil.This study used the modified CLM4.5 wind-blown dust model to simulate the emission of wind-blown dust in Hebei province at 2013.The result shows that:The PM10 from wind-blown dust annual emission flux is 1.02t/hm2 in 2013.The total emission of PM10 is 1925.76 million tons to the atmosphere throughout the year.This study analyzed the characteristics of temporal and spatial variation of wind-blown dust emission of PMio in Hebei Province at 2013.That shows spring is the highest season and summer is the lowest season for wind-blown dust emissions flux.There are obvious seasonal differences about wind-blown dust emissions in Hebei province.There are also obvious regional differences about wind-blown dust emissions in Hebei province.The coastal plain of Cangzhou and Bashang plateau is the highest areas for dust emissions flux and Taihang Mountain Piedmont Plain is the lowest areas.The result above shows CLM4.5 wind-blown dust model can well simulate the characteristics of spatial and temporal change in Hebei Province.The accuracy of the result is verified by the comparative analysis.The comparative is set up between the wind-blown dust emissions of PM10 simulated by CLM4.5 wind-blown dust model with the same area simulated by different models in Hebei Province at 2013.In order to find the relationship between the wind-blown dust emissions of PM10 and the affecting factors,a regression analysis is carried out to determine the influence of the three factors on wind-blown dust of PM10.The three factors are soil moisture,wind speed and the proportion of bare soil.